Text and Data Mining valid from 2019-04-25
Received: 3 September 2018
Accepted: 9 April 2019
First Online: 25 April 2019
Ethics approval and consent to participate
: The study has been approved by the Human Research Ethics Committee, Linköping: no 2013/394–31 and was performed according to the Declaration of Helsinki. Written informed consent was obtained from all study participants.
: Not applicable.
: The authors declare that they have no competing interest.
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